I was picking up some spaghetti during a recent trip to Whole Foods when I realized (gasp!) I’d forgotten bananas. Fighting the steady current of carts as I backtracked to the produce section made me feel like a salmon (wild-caught, never farm-raised) swimming upstream. All the while, smug shoppers gave me the stink-eye as if I’d forgotten my canvas tote and had to schlep my groceries home in a plastic bag.

The jarring experience was enough to get me excited about Instacart (instacart.com), a grocery delivery service that offers same-day drop-offs to addresses in D.C., Bethesda, Chevy Chase, Silver Spring, Takoma Park and Alexandria.

The San Francisco-based startup works with local Whole Foods, Harris Teeter and — just recently — Costco stores, so you can shop a dizzying selection of more than 42,000 products online (no Costco membership needed).

Delivery fees are reasonable: If you’re willing to wait two hours, Instacart charges between $3.99 and $7.99. For deliveries within an hour, the rate jumps to $13.99. And in perhaps the most cost-effective and convenient deal, Costco orders over $35 are dropped off free of charge. That’s a lot of bananas.

Holley Simmons is the dining editor of The Washington Post Express. When she’s not reporting on local restaurants and tastemakers, you can find her sewing a dress from a 1950s pattern or planting a windowsill herb garden. Contact her at holley.simmons@wpost.com.

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